Impact injection pump



p 14, 1965 (3.0. GLASGOW 3,205,824

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United States Patent 3,205,824 IMPACT INJECTION PUMP Clarence 0. Glasgow, 2620 S. Yorktown, Tulsa, Okla. Filed Apr. 10, 1964, Ser. No. 358,774 19 Claims. (Cl. 10338) This invention relates to pumps, and more particularly, relates to pumps capable of injecting relatively small, precisely measured volumes of liquids into a high pressure environment.

There are many manufacturing and industrial situations in which it is desirable to be able to inject a small, relatively precisely measured quantity of a liquid into a high pressure environment. One example of such a situation is the necessity to inject small measured quantities of diesel oil into the cylinders of diesel engines. A number of small fuel injection pumps have previously been proposed for accomplishing this purpose, and in the more recent versions, work quite well to attain the end desired. However, pumps used for this purpose have been relatively expensive to construct, and have been complicated by the inclusion of a number of moving parts which must generally be closely machined and precisely fitted together.

Another situation in which it is desirable to provide a device capable of delivering or injecting a precisely measured quantity of liquid into a high pressure environment is that which is encountered in the oil industry when it is desired to inject a treating fluid into a pipeline carrying oil or gas under pressure. In this situation, it is desirable to have an injection pump which is capable of an extended service life in the course of which no major maintenance problems are presented and in which the pump may be counted upon for trouble-free operation. It is also desirable that an injection pump of this type be adapted for connection to conventional oil well pumping equipment so that the pump may be driven through the same power source used to drive the walking beam or other pumping elements used to produce oil.

The present invention provides a novel and highly useful impact injection pump which is especially well adapted for use in injecting treating chemicals into a pipeline carrying hydrocarbon products under high pressure. The use of the pump is not limited in its utility to this particular adaptation, however, since it may be used in any situation where it is desired to deliver a precisely metered quantity of liquid to a high pressure environment.

Broadly, the present invention may be described as comprising a housing containing the moving parts of the mechanism; a pair of check valves positioned to permit a small quantity of fluid to be drawn into and discharged from the impact injector pump; a small, elongated cylinder in communication with the intake and discharge check valves; a piston element mounted for reciprocation in the cylinder; a flexible member connected to the piston; means for resiliently urging the piston into its cylinder toward a liquid discharging position; lifting cam means connected to the flexible member with said flexible member contacting the lifting cam means over an arcuate surface; means for pivoting the lifting cam means about an axis eccentrically positioned relative to the arcuate surface of the lifting cam means; and means for actuating said lifting cam means through a relatively slow piston withdrawing stroke, and then releasing said lifting cam means for a rapid piston discharging stroke under the influence of said urging means.

In a preferred embodiment of the invention, means are provided for driving the lifting cam actuating means by either electrical power or through a ratchet drive which can be k-inematica-lly connected to the walking beam or other moving portion of an oil well pumping apparatus.

A preferred embodiment of the invention further includes the provision of means for precisely adjusting the stroke of the piston which is used to discharge liquid through the discharge check valve to thereby adjusting with precision, the quantity of liquid which is discharged on each stroke of the piston. The means which is used to resiliently urge or bias the piston into its cylinder upon the discharge stroke exerts sufficient force to develop a relatively high pressure in the liquid during the discharge stroke, and therefore permits a precise quantity of the liquid to be injected into a high pressure environment.

Other refinements and features which can be utilized in several preferred embodiments of the invention will become apparent as the more detailed description of the invention which is hereinafter set forth is studied.

From the foregoing general description of the invention, it will have become apparent that it is a major object of the present invention to provide a mechanically simple, relatively inexpensive, impact injection pump which is capable of delivering a precisely metered quantity of liquid to a high pressure environment.

An additional object of the present invention is to provide an impact injection pump which can be used to inject very small quantities of a liquid chemical into a stream of fluid flowing in pipelines under pressures of as high as 1000 p.s.i.

A further object of the present invention is to provide an impact injection pump which can optionally be driven through a mechanical ratchet drive or by an electrical motor.

A still further object of the present invention is to provide an impact injection pump which includes intake and discharge ball and cone check valves which insure positive, leak-proof shutoif.

Another object of the present invention is to provide an impact injection pump in which the check valves operative during intake and discharge of the pump may be removed and replaced without the necessity to disconnect the inlet and outlet conduits which deliver fluid to and from the pump.

A further object of the present invention is to provide an impact injection pump which is capable of delivering at an accurate and precise injection rate, whether operating at high or low volume output.

An additional object of the present invention is to provide a mechanically sturdy and compact impact injection pump which is characterized in having a long and troublefree operating life.

Other objects and advantages of the present invention, in addition to those which have been hereinbefore described, will become apparent as the following detailed description of the invention is read in conjunction with the accompanying drawings which illustrate the invention.

In the drawings:

FIGURE 1 is a view in elevation illustrating the manner in which the impact injection pump of the invention is mounted for use in injecting a small quantity of a treating :chemi-cal into a pipeline carrying a fluid under high pressure.

FIGURE 2 is a sectional view of one embodiment of the impact injection pump of the invention as the pump appears with one side plate of the housing thereof removed.

FIGURE 3 is a sectional view of the impact injection pump of the invention showing the pum as it appears when the side of the housing which is opposite that shown removed in FIGURE 2 has been removed. FIGURE 3 further illustrates the intake and discharge check valve housing and certain other elements in section.

FIGURE 4 is a vertical sectional view taken through the impact injection pump along line 4-4 as the pump is illustrated in FIGURE 3.

FIGURE 5 is a vertical sectional view taken along line 55 of FIGURE 3.

Referring now to the drawings in detail, and particularly to FIGURE 1, the impact injection pump of the pres" ent invention is designated generally by reference character 10. The impact injection pump is illustrated as being driven by an electric motor 12 through a belt 14 connected to a drive shaft 16. As will be hereinafter more fully explained, the impact injection pump may also be driven through a pawl and ratchet mechanism if this type of drive is preferable. The pump 10 includes a main housing 18 and a valve housing 20 to which are connected an intake conduit 22 and a discharge conduit 24. In one use of the impact injection pump 10, the pump is used to inject small metered quantities of a treating chemical from a storage tank 25 into oil carried in a pipeline 26. In such application of the invention, the discharge conduit 24 may be connected to a suitable injection nozzle 28 which sprays the treating fluid into the oil passing through pipeline 26.

The details of construction of the impact injection pump of the invention may be better undestood by referring to FIGURES 2-5 of the drawings. The main housing 18 of the pump includes a base plate 30 which is integrally cast with a pair of opposed end walls 32 and 34. The housing further includes a pair of side walls 36 and 38 (see FIGURES 4 and 5) which are also preferably cast integrally with the bottom. 30 and end walls 32 and 34. A cover plate closes the top of the housing and is preferably sealed to the end walls 32 and 34 and the side walls 36 and 38 to allow the housing to be filled with a lubricating oil to permit all of the moving parts of the device except the check valves to be continuously lubricated.

' The valve housing 20 is secured to the end wall 34 of the main housing 18 through a mounting bushing 42 'which is constructed of a suitable packing material to afford a fluid-tight sealaround the piston rod of the pump, 'as hereafter explained. Suitable screws 44 are extended through the mounting bushing 42 into the valve housing 20, and other screws (not seen) are extended through the mounting bushing 42 into the end wall 34 of the main housing 18, to retain the valve housing 20 in position.

The valve housing 20 comprises a solid block having threaded bores 46 and 48 formed therein for receiving an externally threaded intake check valve assembly 50, and an externally threaded discharge check valve assembly 52. A cylindrical bore 54 extends through the valve housing 20 in a direction normal to the bores 46 and 48 and communicates therewith in the manner best illustrated in FIGURE 3. Additionally, an internally threaded intake port 56, and an internally threaded discharge port 58 also extend perpendicular to the bores 46 and 48, re- 'spectively, and are in communication therewith. Finally, a counterbore 60 is provided in the side of the valve housing 20 adjacent the main housing 18 and is aligned concentrically, and in communication, with the cylindrical bore 54.

The intake check valve assembly includes a valve retainer body 62 having an intake passageway 64 through the retainer body and aligned with the intake port 56, a generally frusto-conical valve seat 66, and a spherical check valve member 68. O-rings 70, or other suitable sealing members, are provided around the valve retainer body 62 to effectively seal the intake check valve assembly 50 in the valve housing 20.

'The discharge check valve assembly 52is substantially identical to the intake check valve assembly 50, except that a spring 72 is provided for biasing the spherical valve member into contact with its seat when the valve member is not under fluid loading.

The injection mechanism of the pum 10 is predominately contained within the main housing 18. The injection mechanism includes a ratchet wheel 74 which carries ratchet teeth 76 and is rotatably mounted on the drive 4 shaft 16. A suitable key 78 (see FIGURE 4) is used to interlock the ratchet wheel 74' with the drive shaft 16. The drive shaft 16 passes through a suitable hub 80 which is mounted by bolts 82 on the side wall 38 of the main housing 18.

The ratchet wheel 74 is provided with a plurality of circumferentially spaced apertures 84 with three of these apertures being illustrated in the embodiment of the invention shown in the accompanying drawings. The apertures 84 are adapted to receive one or more stub shafts or axles which may take the form of a threaded bolt 86, as illustrated in FIGURE 4. The threaded bolt 86 has a smooth shank portion which is passed through a bushing 88 which rotatably carries a roller 90. In the illustrated embodiment of the invention, only a single roller 90 has been shown as mounted on the ratchet wheel 74 using one of the threaded bolts 86. It will be apparent, however, that two additional rollers 90 could be mounted upon the ratchet wheel in the two additional holes 84 therethrough if this should be desirable. The number of rollers 90 utilized will, as will subsequently become apparent, determine the number of strokes of the pump which occur during each revolution of the ratchet wheel, and thus will determine the frequency of discharge of liquid through the discharge port 58 in the valve housing 20. p

A lifting arm 94 is pivotally mounted at one of its ends 96 upon a shaft 98 which passes through the main housing 18 from one side wall 38 thereof to the other side wall 36. The opposite end 100 of the lifting arm 94 from that which is journaled on the shaft 98 rides upon the roller 90 carried by the ratchet wheel 74 so that the lifting arm 94 is caused to pivot about the shaft 98 as the ratchet wheel rotates.

Also mounted upon the shaft 98 is a lifting cam 102 having a configuration which is perceptible in FIGURES 2 and 3 of the drawings. The lifting cam 102 has a large arcuate lobe portion 104 which is integrally formed with a bifurcated portion 106 which accommodates one end of .a cable 108, or other flexible member. A cable clamp 110 is adjustably secured to the end of the cable 108 and positioned across the bifurcated portion 106 of the lifting cam 102 to retain the cable in the illustrated position.

Several constructions of the lifting arm 94, the lifting cam 102, and the shaft 98 can be used in the invention, For example, in the illustrated embodiment, the lifting arm 94 and lifting cam 102 are shown as integrally formed and therefore constituting a'single operating unit. When formed in this fashion, the integral unit including the lifting arm 94 and lifting cam 102 can be either rotatably mounted on the shaft 98 or can be keyed to the shaft with the shaft mounted rotatably in the side walls 36 and 38 of the main housing 18. Instead of forming the lifting arm 94 and lifting cam 102 as an integral unit, these two elements of the pump structure may be separately formed and then both keyed to the shaft 98 with the shaft mounted for rotation in the walls 36 and 38 of the main housing 18.

For the purpose of limiting the downward movement of the lifting arm 94 and lifting cam 102 about the axis of the shaft 98, a pair of stop screws 114 and 116 are provided. The stop screw 114 is a safety feature which provides a positive stop fixing the lowermost limit of travel of the lifting arm 94. The length of the stop screw 114 which projects downwardly from the lifting arm 94 is preset and maintained at a fixed value for all operations of the pump. This stop screw thus assures that at no time during the operation of the pump will the lifting arm 94 drop below a position in which it can engage the upper surface of the roller 90 carried by the ratchet wheel 74.

The stop screw 116 is an adjustable screw which can be threaded into or out of the main housing 18. A fluted knob 118 is provided to facilitate the adjustment of t length of the screw 116 which projects into the main housing 18. Suitable gasket means 120 is provided around the shank of the adjustable stop screw 116 externally of the end wall 32 of the housing to preserve the fluid-tight integrity of the housing. The inner end 122 of the stop screw 116 bears against a downwardly projecting portion 124 of the lifting cam 102 so as to limit the downward stroke of the lifting arm 94 and lifting cam 102. The function of the adjustable stop screw 116 is to permit the stroke of the impact injection pump to be adjusted as desired, provided only that the length of the stroke is not permitted to exceed that which is permitted by the stop screw 114.

The cable 108 extends through a bifurcation 127 provided in an upstanding spring retainer plate 128 which can be cast as an integral portion of the base plate 30 of the main housing 18. The spring retainer plate 128 restrains against horizontal movement one end 129 of a elical compression spring 130 which extends horizontally in the main housing 18. At its other end 131, the helical compression spring 130 receives a flanged spring guide 132 which is provided with an internally threaded bore 134. The threaded bore 134 receives an externally threaded cable adjusting stud bolt 136 which is adapted to be adjustably positioned within the threaded bore of the spring guide 132. The cable adjusting stud bolt 136 is bored or apertured to permit the cable 108 to be passed therethrough as illustrated in FIGURES 3 and 4. The opposite end of the cable 108 from that which is secured in the cable clamp 110 is secured in a second cable clamp 138 which is positioned inside the threaded bore 134 of the spring guide 132. It will be perceived that the tension in the cable 108 can be adjusted by adjusting the anal relationship between the cable adjusting stud bolt 136 and the spring guide 132.

Threaded into the opposite end of the spring guide 132 from its end carrying the threaded bore 134 is an elongated piston designated by reference character 142. The elongated piston 142 is generally cylindrical in cross section and is provided with a smooth external peripheral surface except for the end 143 which is threaded into the spring guide 132. The opposite end of the elongated piston 142 extends through the mounting bushing 42 and through a packing ring 144 and packing ring follower 146 which are positioned in the bore 60 in the valve housing 20. Suitable O-rings 148 are provided around the packing ring 14 to assure the establishment of a fluidtight seal around the elongated piston 142. The elongated piston 142 terminates with its end positioned in the cylindrical bore 54 in the valve housing 20, and during the operation of the pump in a manner hereinafter described, is driven in reciprocating movement within this bore.

One further operating element is provided within the main housing 18 and functions to facilitate the actuation of the impact injection pump of the invention through a ratchet drive mechanism. This element is the dog or ratchet arm 150 which is rotatably mounted upon a shaft 152 which is in turn mounted in the side wall 38 of the main housing 18. A preferred method of mounting the ratchet arm 150 on the shaft 152 is through the use of a ratchet arm spacer 154 which spaces the ratchet arm inwardly in the housing 18 and also serves as a bushing to permit the ratchet arm 150 to rotate about the shaft 152. The ratchet arm 150 is provided with a tapered end portion 156 so that the ratchet arm can engage the teeth 76 on the ratchet wheel 74.

Operation In describing the operation of the impact injection pump of the invention, it will first be assumed that the pump is being driven by an electric motor in the manner illustrated in FIGURE 1. The motor 12 thus drives the shaft 16 at a constant rate of rotation so that the ratchet wheel 74 keyed to the shaft 16 is also rotated at a constant rate. As the ratchet wheel 74 rotates in a clockwise direction (as viewed in FIGURE 2), the roller carried adjacent the periphery thereof is moved through an arc in a clockwise direction and in so moving, causes the lifting arm 94 to be pivoted upwardly about the axis of shaft 98. Upward pivotation of the lifting arm 94 also produces a counterclockwise pivotal movement of the lifting cam 102 about its axis of rotation. The curvature of the lobe 104 of the lifting cam 102 which is contacted by the cable 103 causes the cable to be pulled toward the end wall 32 of the main housing 18.

Withdrawal of the cable 108 in the indicated direction causes the spring guide 132 to be drawn toward the spring retainer plate 128 to compress the helical compression spring 130. Simultaneously, the elongated piston 142 is moved outwardly in the cylindrical bore 54 of the valve housing 20 to create a suction through the intake port 56 of the valve housing. The spherical intake valve member 68 is unseated, and a treating chemical or other liquid can be drawn into the intake port 56 through the con duit 22 leading to the tank 25 containing the treating chemical.

Withdrawal of the elongated piston 142 from the cylindrical bore 54 continues until the roller 90 carried by the ratchet wheel 74 has been rotated to a position approximately 90 degrees from that shown in FIGURES .2 and 3. This position of the roller 90 may be said to represent the top of the stroke of the impact injection pump. During the withdrawal of the elongated piston 142 from the cylindrical bore 54, the liquid which is to be pumped is sucked into the intake check valve assembly 50 and fills the cylindrical bore 54 and the space between the intake check valve assembly 50 and the discharge check valve assembly 52. This volume can be correlated with certain known positions of the adjustable stop screw 116 as hereinafter explained, to provided for the delivery of a known, precisely metered quantity of liquid.

After the lifting arm 94 has reached the top of its stroke, corresponding to the highest position in the housing 18 of the roller 90, the roller commences to move downwardly as the ratchet wheel 74 continues to rotate. With the downward movement of the roller 90, the lifting arm 94 is released. Since the lifting arm 94 is no longer supported, the compression spring is released and forces the spring guide 132 rapidly toward the end wall 34 of the main housing 18. This movement in turn drives the elongated piston 142 rapidly into the cylindrical bore 54 to eject liquid through the discharge check valve assembly 52 and the discharge port 58. The liquid then flows through the conduit 24 connected to the discharge port 58 and through the injector nozzle 28 into the pipeline 26 carrying oil or other hydrocarbon at a high pressure.

The discharge stroke of the elongated piston 142 in the cylindrical bore 54 is terminated by contact of the downwardly projecting portion 124 of the lifting cam 102 with the inner end of the adjustable stop screw 116. This latter element of the pump may be adjusted to vary the length of stroke of the elongated piston 142 so as to precisely control the amount of liquid delivered by the pump upon each stroke. The stop screw 114 which is threaded through the lifting arm 94, as illustrated in FIGURE 2, is a safety feature which assures that in the event the adjustable stop screw 116 has been inadvert ently threaded outwardly in the housing 18 to an undesirable extent, the lifting arm 94 and lifting cam 102 will not be permitted to continue their downwardly pivotal movement to an extent such that the elongated piston 142 will be driven into the bores 46 and 48 which receive the intake and discharge check valve assemblies 50 and 52, respectively. The action of the stop screw 114 also assures that the lifting arm 94 cannot be depressed by the spring 130 to a point where it cannot be subsequently engaged and lifted by the roller 90 during rotation of the ratchet wheel 74.

Having described one cycle of operation of the impact injection pump, it is believed that certain particularly useful features of the illustrated embodiment of the invention should be discussed. As has previously been mentioned, in situations Where it is desired that more frequent and shorter strokes be developed by the pump on each rotation of the ratchet wheel '74, rollers identical to the roller 90 may be mounted in each of the apertures 84 provided just inwardly of the periphery of the ratchet wheel 74 so that a number of strokes per revolution of the wheel corresponding to the number of rollers provided may be obtained. It should also be noted that the tension under which the cable 108 is placed may be altered as desired by adjustment of the position of the cable clamps 116 and 138. Finally, the relative length of the elongated piston 142 may be adjusted by threading the piston into or out of the spring guide 132 as may be desired.

Yet another useful feature of the present invention is the manner in which the valve housing and its associated valve components are constructed. Thus, it will be perceived that both the intake check valve assembly 50 and the discharge check. valve assembly 52 may be removed from their respective bores 48 and 46 without the necessity to disconnect the conduits 22 and 24 from the intake port 56 and discharge port 58, respectively. Also, the ball and cone design of the check valves used in the invention assures positive seating of the valves with very little leakage at the high pressures at which the pump is designed to operate.

A final important aspect of the invention deserves some elucidation. In many instances, it may be desirable to operate the impact injection pump of the invention by a mechanical, ratchet-type drive instead of the electric drive which is illustrated in FIGURE 1. For example, the ratchet-type drive is especially useful where the impact injection pump is to be positioned adjacent an oil well and used to pump a treating liquid into the pipeline carrying oil under pressure. In this situation, a ratchet mechanism well known to the art may be interconnected between the walking beam of a conventional sucker rodtype oil well pump and the shaft 16 of the impact injection pump. This type of drive imparts an intermittent rotating motion to the ratchet wheel 74, and, in most instances, the spring loaded mechanism of such ratchet drives will cause the ratchet wheel 7 4 to tend to rotate in a counterclockwise direction (as viewed in FIGURE 2) unless a positive stop is provided to prevent such counterclockwise rotation. To this end, the ratchet arm 15d has been provided as an integral part of the impact injection pump of the invention, and functions to prevent rotation of the ratchet wheel 74 in a counterclockwise direction.

From the foregoing description of the invention, it will have become apparent that the present invention constitutes a relatively simple, yet highly eflicient pump, which may be used to pump relatively small and accurately metered quantities of a liquid at a high pressure. The pump is versatile in its construction and operation so that the volume of liquid pumped upon each stroke of the pump may be adjusted as desired, and a plurality of types of prime movers may be connected to the pump. The number of moving parts of the pump is relatively small, as compared to previous types of impact injection pumps, and the parts utilized are of sturdy construction so that the pump is characterized by a long and trouble-free operating life.

Although a preferred embodiment of the invention has been hereinbefore described by way of example, it can be readily perceived that certain innovations and modifications can be made in the described structure without a meaningful departure from the basic principles which underlie the invention. It is therefore intended that all such modifications and innovations shall be circumscribed by the spirit and scope of the invention unless the changes made in the hereinbefore described structure involve a clear departure from the principles and concepts constituting the basis of the invention.

What is claimed is:

1. An impact injection pump comprising:

a body containing a cylindrical bore, and having intake and discharge passageway means communicating with said cylindrical bore for conducting a fluid between said cylindrical bore and the outside of said body;

an elongated piston reciprocably mounted in said bore;

an elongated flexible member having two ends and having one of its ends connected to one end of said piston;

piston retracting means spaced from said body and secured to the other end of said elongated flexible member;

means pivotally supporting said piston retracting means for pivoting in a direction to reciprocate said flexible member along the projected axis of said cylindrical bore; 1

a spring resiliently biasing said piston into said cylindrical bore;

a spring retainer limiting movement of said spring along the projected axis of said cylindrical bore; and

means periodically biasing said piston retracting means about its pivotal axis in a direction to retract said piston from said cylindrical bore, and releasing said piston retracting means after said retracting movement to permit said spring to resiliently bias said piston into said cylindrical bore.

2. An impact injection pump as claimed in claim 1 wherein said piston retracting means comprises:

a lifting cam secured to the other end of said flexible member for pulling said flexible member along a line coincident with the projected axis of said cylindrical bore when said piston retracting means is pivoted about its pivotal axis in one direction; and

a lifting arm periodically cooperating with said periodic biasing means and connected to said lifting cam.

3. An impact injection pump as claimed in claim 1 wherein said means periodically biasing said piston retracting means comprises:

a drive shaft adapted for connection to a prime mover;

and

a biasing element connected to said drive shaft and radially offset from the axis thereof for rotation about said axis when said drive shaft is rotated, said biasing element periodically cooperating with said piston retracting means to pivot said piston retracting means about its pivotal axis in a direction to retract said piston in said cylindrical bore and being periodically disengaged from said piston retracting means to permit said spring to resiliently bias said piston into said cylindrical bore.

4. An impact injection pump as claimed in claim 1 and further characterized to include intake and discharge check valves mounted in said intake and discharge passageway means, said intake and discharge passageway means having an intake port and a dischrge port extending into said body and further including valve bores extending into said body to said intake and discharge ports in a direction substantially normal to the axes of said intake and discharge ports and accommodating said intake and discharge check valves whereby said check valves can be removed from their respective bores without disconnecting conduits from said intake and discharge ports.

5. An impact injection pump as claimed in claim 1 wherein said flexible member is connected to said piston through a spring guide, and said spring is a helical compression spring surrounding a part of said flexible member and having one of its ends abutting said spring retainer, its other end abutting said spring guide.

6. An impact injection pump as claimed in claim 1 wherein said body comprises a valve housing having a pair of check valve receiving bores extending thereinto,

9 a discharge port extending into said housing and intersecting one of said check valve receiving bores substantially at a right angle, an intake port extending into said housing and intersecting the other of said check valve receiving bores substantially at a right angle, and having said cylindrical bore communicating with said check valve receiving bores, said impact injection pump further having an intake check valve in one of said check valve receiving bores and having a discharge check valve in the other of said check valve receiving bores whereby said check valves may be removed from said check valve housing without disconnecting the conduit system from said intake and discharge ports.

7. An impact injection pump as claimed in claim 1 wherein said flexible means is a flexible cable, and said piston retracting means comprises:

a lifting earn having an arcuate cam surface to which said cable is attached; and

a lifting arm connected to said lifting cam for movement therewith;

and wherein said means pivotally supporting said piston retracting means comprises a shaft pivotally supporting said lifting cam and lifting arm and positioned in a plane extending substantially normal to the projected axis of said cylindrical bore.

8. An impact injection pump as claimed in claim 7 wherein said means periodically biasing said piston retracting means about its pivotal axis comprises:

a drive shaft adapted for connection to a prime mover;

a ratchet wheel connected to said drive shaft for rotation therewith and having ratchet teeth around the outer periphery thereof;

a roller supported on said ratchet wheel and spaced radially outwardly from the axis of said drive shaft; and

a ratchet arm adapted to engage the teeth of said ratchet wheel to prevent rotation of said ratchet wheel in one direction, said roller cooperating with said lifting arm during a portion of one rotation of said ratchet wheel to pivot said lifting arm and its associated lifting cam about said pivotally supporting shaft, whereby said elongated piston may be reciprocated outwardly in said cylindrical bore during said portion of one rotation of the ratchet wheel.

9. An impact injection pump comprising:

a rotatably mounted drive shaft;

a lifting member carried by said drive shaft in radially spaced relation to the axis of said drive shaft and supported on said drive shaft for rotation concentrically around the axis thereof;

pivotally mounted lifting cam means adjacent said rotatably mounted drive shaft and having a projecting lifting arm portion cooperating with said lifting member during a portion of one revolution of said drive shaft, said lifting cam means further having an arcuate cam surface;

a body containing an intake passageway, a discharge passageway, and a bore communicating with said intake and discharge passageway;

piston means extending into said bore and connected to said lifting cam means for withdrawal of said piston means from said bore when said lifting cam means is pivoted about its pivotal axis, and said lifting arm portion is cooperating with said lifting member;

spring means biasing said piston means inwardly into said bore when cooperation between said lifting arm portion and said lifting member is terminated by the continued rotation of said drive shaft; and

a housing containing all of the elements of said impact injection pump except said body, a portion of said piston means and a portion of said drive shaft whereby the elements of said pump inside said housing may be continuously lubricated by a lubricant contained within said housing.

10. An impact injection pump comprising:

a rotatably mounted drive shaft;

circular wheel means keyed to said drive shaft for rotation therewith, said circular wheel means containing a plurality of apertures therethrough radially spaced from said drive shaft and circumferentially spaced from each other around said circular wheel means;

at least one lifting arm follower mounted in at least one of said apertures and each projecting from said wheel means in a direction substantially parallel to said drive shaft;

pivotally mounted lifting cam means adjacent said rotatably mounted drive shaft and having a projecting lifting arm portion extending into contact with each of said lifting arm followers during a portion of each revolution of said drive shaft, said apertures and all the lifting arm followers mounted thereon being spaced from each other and dimensioned so that said lifting arm portion contacts and cooperates with each of said lifting arm followers during a separate portion of each revolution of said drive shaft, said lifting cam means further having an arcuate cam surface; i

a body containing an intake passageway, a discharge passageway, and a bore communicating with said intake and discharge passageways;

piston means extending into said bore and connected to said lifting cam means for withdrawal of said piston means from said bore when said lifting cam means is pivoted about its pivotal axis, and said lifting arm portion is cooperating with one of said lifting arm followers; and

spring means biasing said piston means inwardly into said cylindrical bore when cooperation between said lifting arm portion and all of said lifting arm followers is terminated by the continued rotation of said drive shaft.

11. An impact injection pump comprising:

a rotatably mounted drive shaft;

a lifting member carried by said drive shaft in radially spaced relation to the axis of such shaft and supported on such shaft for rotation concentrically around the axis thereof;

pivotally mounted lifting cam means adjacent said rotatably mounted drive shaft and having a projecting lifting arm portion cooperating with said lifting member during a portion of one revolution of said drive shaft, said lifting cam means further having an arcuate cam surface;

a body containingan intake passageway, a discharge passageway, and a cylindrical bore communicating with said intake and discharge passageways;

piston means extending into said cylindrical bore and connected to said lifting cam means for withdrawal of said piston means from said cylindrical bore when said lifting cam means is pivoted about its pivotal axis, and said lifting arm portion is cooperating with said lifting member;

spring means biasing said piston means inwardly into said cylindrical bore when cooperation between said lifting arm portion and said lifting member is terminated by the continued rotation of said drive shaft; and

means for adjusting the length of the stroke of said piston means in its movement in said cylindrical bore; and

means for maintaining the piston in its start-of-stroke position in said bore when the length of stroke of the piston is adjusted by said stroke length adjusting means.

12. An impact injection pump comprising:

a rotatably mounted drive shaft;

a lifting member carried by said drive shaft in radially spaced relation to the axis of said drive shaft and supported on said shaft for rotation concentrically around the axis thereof;

pivotally mounted lifting cam means adjacent said rotatably mounted drive shaft and having a projecting lifting arm portion cooperating with said lifting member during a portion of one revolution of said drive shaft, said lifting cam means further having an arcuate cam surface;

a body containing an intake passageway, a discharge passageway, and a cylindrical bore communicating with said intake and discharge passageways, said cylindrical bore having an axis, which, when projected, extends normal to a plane containing the pivotal axis of said lifting cam means, and wherein the projected axis of said cylindrical bore extends tangentially to said arcuate cam surface;

piston means extending into said cylindrical bore and connected to said lifting cam means for Withdrawal of said piston means from said cylindrical bore when said lifting cam means is pivoted about its pivotal axis, and said lifting arm portion is cooperating with said lifting member; and

spring means biasing said piston means inwardly into said cylindrical bore when cooperation between said lifting arm portion and said lifting member is terminated by the continued rotation of said drive shaft.

13. An impact injection pump as claimed in claim 12 wherein said piston means comprises:

an elongated piston extending into said cylindrical bore;

and

a flexible cable connected at one of its ends to said elongated piston and at its other end to said arcuate cam surface whereby said flexible cable is drawn along the projected axis of said cylindrical bore when said lifting cam means is pivoted about its pivotal axis in one direction.

14. An impact injection pump as claimed in claim 13 and further characterized to include a housing surrounding all of the elements of said impact injection pump except said body and a portion of said elongated piston whereby the elements of said pump inside said housing may be continuously lubricated by a lubricant contained within said housing.

said spring means is a helical compression spring surrounding said flexible cable and having one of its ends abutting said spring retainer plate and its other end connected to said flexible cable for compression of said helical compression spring when said cable is drawn along the projected axis of said cylindrical bore by pivotation of said pivotally mounted lifting cam means in one direction.

16. An impact injection pump comprising: a cylinder; a piston reciprocably mounted in said cylinder; a flexible piston retracting member connected by one of its ends to one end of said piston; cam means connected to the other end of said flexible piston retracting member and pivotally mounted for drawing said flexible piston retracting member and said piston along the projected axis of said cylinder to move the piston outwardly in said cylinder when said cam means is pivoted about its pivotal axis;

a rotating cam actuating device periodically cooperating with said cam means to pivot said cam means about its pivotal axis in a direction to move said piston outwardly in said cylinder;

means biasing said piston inwardly into said cylinder during rotation of said rotating cam actuating device in the period over which cooperation between said cam means and said cam actuating device is interrupted; and

valve means for alternately admitting fluid to said cylinder from a first location during movement of said piston outwardly in said cylinder and discharging fluid from said cylinder to a second location during movement of said piston inwardly into said cylinder.

17. An impact injection pump as claimed in claim 16 wherein said cam means comprises:

a lifting arm;

a lifting cam connected to said lifting arm for movement therewith; and

a shaft mutually supporting said lifting arm and said lifting cam for mutual pivotation about the axis of said shaft;

and wherein said rotating cam actuating device comprises:

a rotatably mounted wheel carrying a radially offset lifting arm follower positioned to cooperate with said lifting arm during a portion of one rotation of said rotatably mounted wheel; and

means for driving said rotatably mounted wheel in rotation.

18. An impact injection pump as claimed in claim 17 wherein said biasing means comprises a compression spring adapted to be compressed during said portion of one rotation of said rotatably mounted wheel and released from compression during the remaining portion of said one rotation of said rotatably mounted wheel.

19. An impact injection pump comprising: an'elongated cylinder; check valve means for alternately admitting fluid to, and releasing fluid from, said elongated cylinder; a piston mounted for reciprocation in the cylinder; means for resiliently urging the piston into its cylinder toward a fluid discharging position; a flexible member connected to the piston; lifting cam means connected to the flexible member with said flexible member contacting the lifting cam means over an arcuate surface; means for pivoting the lifting cam means about an axis eccentrically positioned relative to the arcuate surface of the lifting cam means and positioned in a plane extending substantially normal to the projected axis of said cylindrical bore; and, means for actuating said lifting cam means through a relatively slow piston withdrawing stroke, and then releasing said lifting cam means for a rapid piston discharging stroke under the influence of said urging means.

References Cited by the Examiner UNITED STATES PATENTS 781,891 2/05 Lockwood 103-213 X 1,108,804 8/14 Sperry 103-2l1 1,277,382 9/18 Chapman et a1. l03-2l0 X ROBERT M. WALKER, Primary Examiner. 

1. AN IMPACT INJECTION PUMP COMPRISING: A BODY CONTAINING A CYLINDRICAL BORE, AND HAVING INTAKE AND DISCHARGE PASSAGEWAY MEANS COMMUNICATING WITH SAID CYLINDRICAL BORE FOR CONDUCTING A FLUID BETWEEN SAID CYLINDRICAL BORE AN D THE OUTSIDE OF SAID BODY; AN ELONGATED PISTON RECIPROCABLY MOUNTED IN SAID BORE; AN ELONGATED FLEXIBLE MEMBER HAVING TWO ENDS AND HAVING ONE OF ITS ENDS CONNECTED TO ONE END OF SAID PISTON; PISTON RETRACTING MEANS SPACED FROM SAID BODY AND SECURED TO THE OTHER END OF SAID ELONGATED FLEXIBLE MEMBER; MEANS PIVOTALLY SUPPORTING SAID PISTON RETRACTING MEANS FOR PIVOTING IN A DIRECTION TO RECIPROCATE SAID FLEXIBLE MEMBER ALONG THE PROJECTED AXIS OF SAID CYLINDRICAL BORE; A SPRING RESILIENTLY BIASING SAID PISTON INTO SAID CYLINDRICAL BORE; A SPRING RETAINER LIMITING MOVEMENT OF SAID SPRING ALONG THE PROJECTED AXIS OF SAID CYLINDRICAL BORE; AND MEANS PERIODICALLY BIASING SAID PISTON RETRACTING MEANS ABOUT ITS PIVOTAL AXIS IN A DIRECTION TO RETRACT SAID PISTON FROM SAID CYLINDRICAL BORE, AND RELEASING SAID PISTON RETRACTING MEANS AFTER SAID RETRACTING MOVEMENT TO PERMIT SAID SPRING TO RESILIENTLY BIAS SAID PISTON INTO SAID CYLINDRICAL BORE. 